Google yesterday took the wraps off a new hosted software platform offering developers access to Google's scalable infrastructure.

The company's App Engine service -- which will be offered free to developers during a preview period -- includes a software development kit, enabling developers to write Web applications and upload them to the company's servers for hosting.

Also through the service, which Google (NASDAQ: GOOG) unveiled yesterday during its Campfire One developer event, application developers will have access to persistent storage technologies such as the Google File System (GFS) and Bigtable, a distributed storage system for unstructured data.

"With Google App Engine, developers can write Web applications based on the same building blocks that Google uses," Kevin Gibbs, Google's technical lead for the project, wrote in a company blog. "Google App Engine packages those building blocks and provides access to scalable infrastructure that we hope will make it easier for developers to scale their applications automatically as they grow."

The offering comes at a time when an increasing number of tech companies are moving their operations to the cloud, and places Google squarely in competition with Amazon's (NASDAQ: AMZN) Elastic Cloud Computing (EC2) and Simple Storage Service (S3) offerings.

It may be getting crowded up there on the cloud, but Google is betting that its flexible hosting capability -- and its reputation as a data-management and -serving giant -- will give it the inside track.

"There are a lot of good services out there right now that give developers building blocks for Web apps," a Google spokesman told InternetNews.com. "Our vision with Google App Engine is to offer developers a more holistic, end-to-end solution for building and scaling applications online."

Google added that its servers are configured to balance the load of traffic to developers' applications, scaling to meet the demand of an influx of traffic. App Engine also includes APIs for user authentication to allow developers to sign on for services, and for e-mail, to manage communications.

Through its initial preview, Google's App Engine will be available free to the first 10,000 developers who sign up, with plans to expand that number in the future.

During that period, users will be limited to 500MB of storage, 10GB of daily bandwidth and 5 million daily page views, the company said. Developers will be able to register up to three applications.

Following the end of the preview period, Google expects to begin selling additional computing resources beyond these limits, it said.

Google, which plans to continue offering a free, basic level of App Engine service even after the initial period, declined to provide specifics on future pricing for additional resources.